Overview

This is an implementation of a Model Predictive Path Integral (MPPI) controller which uses IsaacGym as a dynamic model for the rollouts. We provide several examples of what tasks you can solve with it:

You can extend the repository with your robots and tasks since it is designed to be modular and reusable.

How to cite this work

If you found this repository useful, please consider citing the associated paper below:

@misc{pezzato2023samplingbased,
      title={Sampling-based Model Predictive Control Leveraging Parallelizable Physics Simulations}, 
      author={Corrado Pezzato and Chadi Salmi and Max Spahn and Elia Trevisan and Javier Alonso-Mora and Carlos Hernandez Corbato},
      year={2023},
      eprint={2307.09105},
      archivePrefix={arXiv},
      primaryClass={cs.RO}
}

Installation

NOTE: To use the GPU pipeline (default) you need an NVIDIA graphics card. If you do not have one, you can use the CPU pipeline, with fewer samples.

This project requires the source code of IsaacGym inside the folder thirdparty. Download it from https://developer.nvidia.com/isaac-gym, extract it, and place it in mppi-isaac/thirdparty. Then you can proceed with the installation described below.

Virtual environment (advised)

You can install the necessary dependencies using poetry virtual environment. After installing poetry, move into mppi-isaac and run

poetry install --with dev

Bear in mind that the installation might take several minutes the first time. But it's worth it.

Access the virtual environment using

poetry shell

Virtual environment - Pycharm

If you are using Pycharm (professional), first add a new Python interpreter via 'Add New Interpreter', 'Add local interpreter" and create a virtual environment within the mppi-isaac folder called 'venv'. Then install the necessary dependencies using poetry in the virtual environment.

poetry install --with dev

Test the installation

Test that everything is properly set up, use pytest

cd examples
poetry run pytest

System-level installation

Alternatively, you can also install at the system level using pip, even though we advise using the virtual environment:

pip install .

Troubleshooting

If you have an Nvidia card and after running the simulation you get a black screen, you might need to force the use of the GPU card through export VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/nvidia_icd.json. Run this command from the same folder as the script to be launched for every terminal

Running the examples

Access the virtual environment if installed with poetry (with poetry shell). You can run two types of examples, either the ones using IsaacGym or the ones using Pybullet. In the examples folder, you find all the scripts.

IsaacGym examples

To run the examples with IsaacGym (panda, heijn_push, boxer_push, albert and more), you need two terminals because it is required to run a "server" and a "client" script. In the first one run the server:

python3 world.py

In the second one the client:

python3 planner.py

Pybullet examples

In some older branches, you can run one of the example scripts which use Pybullet, for instance for the panda robot:

python3 panda_robot_with_obstacles.py